The present invention relates to a catalyst composition comprising at least two metal compounds useful in olefin polymerization processes to produce polyolefins. Preferably, at least one of the metal compounds is a Group 15 containing metal compound. More preferably, the other metal compound is a bulky ligand metallocene-type catalyst. The present invention also relates to a new polyolefin, generally polyethylene, particularly a multimodal polymer and more specifically, a bimodal polymer, and its use in various end-use applications such as film, molding and pipe.
Polyethylenes with a higher density and higher molecular weight are valued in film applications requiring high stiffness, good toughness and high throughput. Such resins are also valued in pipe applications requiring stiffness, toughness and long-term durability, and particularly resistance to environmental stress cracking.
Typical metallocene polymerization catalysts (i.e. those containing a transition metal bound, for example, to at least one cyclopentadienyl, indenyl or fluorenyl group) have recently been used to produce resins having desirable product properties. While these resins have excellent toughness properties, particularly dart impact properties, they, like other metallocene catalyzed polyethylenes, can be difficult to process, for example, on older extrusion equipment. One of the means used to improve the processing of such metallocene catalyzed polyethylenes is to blend them with another polyethylene. While the two polymer blend tends to be more processable, it is expensive and adds a cumbersome blending step to the manufacturing/fabrication process.
Higher molecular weight confers desirable mechanical properties and stable bubble formation onto polyethylene polymers. However, it also inhibits extrusion processing by increasing backpressure in extruders, promotes melt fracture defects in the inflating bubble and potentially, promotes too high a degree of orientation in the finished film. To remedy this, one may form a secondary, minor component of lower molecular weight polymer to reduce extruder backpressure and inhibit melt fracture. Several industrial processes operate on this principle using multiple reactor technology to produce a processable bimodal molecular weight distribution (MWD) high density polyethylene (HDPE) product. HIZEX(trademark), a Mitsui Chemicals HDPE product, is considered the worldwide standard. HIZEX(trademark) is produced in two or more reactors and is costly to produce. In a multiple reactor process, each reactor produces a single component of the final product.
Others in the art have tried to produce two polymers together at the same time in the same reactor using two different catalysts. PCT patent application WO 99/03899 discloses using a typical metallocene catalyst and a conventional Ziegler-Natta catalyst in the same reactor to produce a bimodal MWD HDPE. Using two different types of catalysts, however, result in a polymer whose characteristics cannot be predicted from those of the polymers that each catalyst would produce if utilized separately. This unpredictability occurs, for example, from competition or other influence between the catalyst or catalyst systems used. These polymers however still do not have a preferred balance of processability and strength properties. Thus, there is a desire for a combination of catalysts capable of producing processable polyethylene polymers in preferably a single reactor having desirable combinations of processing, mechanical and optical properties.
The present invention provides a catalyst composition, a polymerization process using the catalyst composition, polymer produced therefrom and products made from the polymer.
In one embodiment, the invention is directed to a catalyst composition including at least two metal compounds, where at least one metal compound is a Group 15 containing metal compound, and where the other metal compound is a bulky ligand metallocene-type compound, a conventional transition metal catalyst, or combinations thereof.
In one embodiment, the invention is directed to a catalyst composition including at least two metal compounds, where at least one metal compound is a Group 15 containing bidentate or tridentate ligated Group 3 to 14 metal compound, preferably a Group 3 to 7, more preferably a Group 4 to 6, and even more preferably a Group 4 metal compound, and where the other metal compound is a bulky ligand metallocene-type compound, a conventional transition metal catalyst, or combinations thereof. In this embodiment it is preferred that the other metal compound is a bulky ligand metallocene-type compound.
In another embodiment, the invention is directed to a catalyst composition including at least two metal compounds, where one metal compound is a Group 3 to 14 metal atom bound to at least one leaving group and also bound to at least two Group 15 atoms, at least one of which is also bound to a Group 15 or 16 atom through another group, and where the second metal compound, is different from the first metal compound, and is a bulky ligand metallocene-type catalyst, a conventional-type transition metal catalyst, or combinations thereof.
In an embodiment, the invention is directed to processes for polymerizing olefin(s) utilizing the above catalyst compositions, especially in a single polymerization reactor.
In yet another embodiment, the invention is directed to the polymers prepared utilizing the above catalyst composition, preferably to a new bimodal MWD HDPE.
Introduction
The present invention relates to the use of a mixed catalyst composition where one of the catalysts is a Group 15 containing metal compound. Applicants have discovered that using these compounds in combination with another catalyst, preferably a bulky ligand metallocene type compound, produces a new bimodal MWD HDPE product. Surprisingly, the mixed catalyst composition of the present invention may be utilized in a single reactor system.
Group 15 Containing Metal Compound
The mixed catalyst composition of the present invention includes a Group 15 containing metal compound. The Group 15 containing compound generally includes a Group 3 to 14 metal atom, preferably a Group 3 to 7, more preferably a Group 4 to 6, and even more preferably a Group 4 metal atom, bound to at least one leaving group and also bound to at least two Group 15 atoms, at least one of which is also bound to a Group 15 or 16 atom through another group.
In one preferred embodiment, at least one of the Group 15 atoms is also bound to a Group 15 or 16 atom through another group which may be a C1 to C20 hydrocarbon group, a heteroatom containing group, silicon, germanium, tin, lead, or phosphorus, wherein the Group 15 or 16 atom may also be bound to nothing or a hydrogen, a Group 14 atom containing group, a halogen, or a heteroatom containing group, and wherein each of the two Group 15 atoms are also bound to a cyclic group and may optionally be bound to hydrogen, a halogen, a heteroatom or a hydrocarbyl group, or a heteroatom containing group.
In a preferred embodiment, the Group 15 containing metal compound of the present invention may be represented by the formulae: 
wherein
M is a Group 3 to 12 transition metal or a Group 13 or 14 main group metal, preferably a Group 4, 5, or 6 metal, and more preferably a Group 4 metal, and most preferably zirconium, titanium or hafnium,
each X is independently a leaving group, preferably, an anionic leaving group, and more preferably hydrogen, a hydrocarbyl group, a heteroatom or a halogen, and most preferably an alkyl.
y is 0 or 1 (when y is 0 group Lxe2x80x2 is absent),
n is the oxidation state of M, preferably +3, +4, or +5, and more preferably +4,
m is the formal charge of the YZL or the YZLxe2x80x2 ligand, preferably 0, xe2x88x921, xe2x88x922 or xe2x88x923, and more preferably xe2x88x922,
L is a Group 15 or 16 element, preferably nitrogen,
Lxe2x80x2 is a Group 15 or 16 element or Group 14 containing group, preferably carbon, silicon or germanium,
Y is a Group 15 element, preferably nitrogen or phosphorus, and more preferably nitrogen,
Z is a Group 15 element, preferably nitrogen or phosphorus, and more preferably nitrogen,
R1 and R2 are independently a C1 to C20 hydrocarbon group, a heteroatom containing group having up to twenty carbon atoms, silicon, germanium, tin, lead, or phosphorus, preferably a C2 to C20 alkyl, aryl or aralkyl group, more preferably a linear, branched or cyclic C2 to C20 alkyl group, most preferably a C2 to C6 hydrocarbon group.
R3 is absent or a hydrocarbon group, hydrogen, a halogen, a heteroatom containing group, preferably a linear, cyclic or branched alkyl group having 1 to 20 carbon atoms, more preferably R3 is absent, hydrogen or an alkyl group, and most preferably hydrogen
R4 and R5 are independently an alkyl group, an aryl group, substituted aryl group, a cyclic alkyl group, a substituted cyclic alkyl group, a cyclic aralkyl group, a substituted cyclic aralkyl group or multiple ring system, preferably having up to 20 carbon atoms, more preferably between 3 and 10 carbon atoms, and even more preferably a C1 to C20 hydrocarbon group, a C1 to C20 aryl group or a C1 to C20 aralkyl group, or a heteroatom containing group, for example PR3, where R is an alkyl group,
R1 and R2 may be interconnected to each other, and/or R4 and R5 may be interconnected to each other,
R6 and R7 are independently absent, or hydrogen, an alkyl group, halogen, heteroatom or a hydrocarbyl group, preferably a linear, cyclic or branched alkyl group having 1 to 20 carbon atoms, more preferably absent, and
R* is absent, or is hydrogen, a Group 14 atom containing group, a halogen, a heteroatom containing group.
By xe2x80x9cformal charge of the YZL or YZLxe2x80x2 ligandxe2x80x9d, it is meant the charge of the entire ligand absent the metal and the leaving groups X.
By xe2x80x9cR1 and R2 may also be interconnectedxe2x80x9d it is meant that R1 and R2 may be directly bound to each other or may be bound to each other through other groups. By xe2x80x9cR4 and R5 may also be interconnectedxe2x80x9d it is meant that R4 and R5 may be directly bound to each other or may be bound to each other through other groups.
An alkyl group may be a linear, branched alkyl radicals, or alkenyl radicals, alkynyl radicals, cycloalkyl radicals or aryl radicals, acyl radicals, aroyl radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonyl radicals, carbomoyl radicals, alkyl- or dialkyl-carbamoyl radicals, acyloxy radicals, acylamino radicals, aroylamino radicals, straight, branched or cyclic, alkylene radicals, or combination thereof. An aralkyl group is defined to be a substituted aryl group.
In a preferred embodiment R4 and R5 are independently a group represented by the following formula: 
wherein
R8 to R12 are each independently hydrogen, a C1 to C40 alkyl group, a halide, a heteroatom, a heteroatom containing group containing up to 40 carbon atoms, preferably a C1 to C20 linear or branched alkyl group, preferably a methyl, ethyl, propyl or butyl group, any two R groups may form a cyclic group and/or a heterocyclic group. The cyclic groups may be aromatic. In a preferred embodiment R9, R10 and R12 are independently a methyl, ethyl, propyl or butyl group (including all isomers), in a preferred embodiment R9, R10 and R12 are methyl groups, and R8 and R11 are hydrogen.
In a particularly preferred embodiment R4 and R5 are both a group represented by the following formula: 
In this embodiment, M is a Group 4 metal, preferably zirconium, titanium or hafnium, and even more preferably zirconium; each of L, Y, and Z is nitrogen; each of R1 and R2 is xe2x80x94CH2xe2x80x94CH2xe2x80x94; R3 is hydrogen; and R6 and R7 are absent.
In a particularly preferred embodiment the Group 15 containing metal compound is represented by the formula: 
In compound I, Ph equals phenyl.
The Group 15 containing metal compounds of the invention are prepared by methods known in the art, such as those disclosed in EP 0 893 454 A1, U.S. Pat. No. 5,889,128 and the references cited in U.S. Pat. No. 5,889,128 which are all herein incorporated by reference. U.S. application Ser. No. 09/312,878, filed May 17, 1999, discloses a gas or slurry phase polymerization process using a supported bisamide catalyst, which is also incorporated herein by reference.
A preferred direct synthesis of these compounds comprises reacting the neutral ligand, (see for example YZL or YZLxe2x80x2 of formula 1 or 2) with MnXn (M is a Group 3 to 14 metal, n is the oxidation state of M, each X is an anionic group, such as halide, in a non-coordinating or weakly coordinating solvent, such as ether, toluene, xylene, benzene, methylene chloride, and/or hexane or other solvent having a boiling point above 60xc2x0 C., at about 20 to about 150xc2x0 C. (preferably 20 to 100xc2x0 C.), preferably for 24 hours or more, then treating the mixture with an excess (such as four or more equivalents) of an alkylating agent, such as methyl magnesium bromide in ether. The magnesium salts are removed by filtration, and the metal complex isolated by standard techniques.
In one embodiment the Group 15 containing metal compound is prepared by a method comprising reacting a neutral ligand, (see for example YZL or YZLxe2x80x2 of formula 1 or 2) with a compound represented by the formula MnXn (where M is a Group 3 to 14 metal, n is the oxidation state of M, each X is an anionic leaving group) in a non-coordinating or weakly coordinating solvent, at about 20xc2x0 C. or above, preferably at about 20 to about 100xc2x0 C., then treating the mixture with an excess of an alkylating agent, then recovering the metal complex. In a preferred embodiment the solvent has a boiling point above 60xc2x0 C., such as toluene, xylene, benzene, and/or hexane. In another embodiment the solvent comprises ether and/or methylene chloride, either being preferable.
Bulky Ligand Metallocene-Type Compound
In addition to the Group 15 containing metal compound, the mixed catalyst composition of the present invention also includes a second metal compound, which is preferably a bulky ligand metallocene-type compound.
Generally, bulky ligand metallocene-type compounds include half and full sandwich compounds having one or more bulky ligands bonded to at least one metal atom. Typical bulky ligand metallocene-type compounds are generally described as containing one or more bulky ligand(s) and one or more leaving group(s) bonded to at least one metal atom. In one preferred embodiment, at least one bulky ligands is xcex7-bonded to the metal atom, most preferably xcex75-bonded to the metal atom.
The bulky ligands are generally represented by one or more open, acyclic, or fused ring(s) or ring system(s) or a combination thereof. These bulky ligands, preferably the ring(s) or ring system(s) are typically composed of atoms selected from Groups 13 to 16 atoms of the Periodic Table of Elements, preferably the atoms are selected from the group consisting of carbon, nitrogen, oxygen, silicon, sulfur, phosphorous, germanium, boron and aluminum or a combination thereof. Most preferably the ring(s) or ring system(s) are composed of carbon atoms such as but not limited to those cyclopentadienyl ligands or cyclopentadienyl-type ligand structures or other similar functioning ligand structure such as a pentadiene, a cyclooctatetraendiyl or an imide ligand. The metal atom is preferably selected from Groups 3 through 15 and the lanthanide or actinide series of the Periodic Table of Elements. Preferably the metal is a transition metal from Groups 4 through 12, more preferably Groups 4, 5 and 6, and most preferably the transition metal is from Group 4.
In one embodiment, the bulky ligand metallocene-type catalyst compounds are represented by the formula:
LALBMQnxe2x80x83xe2x80x83(III) 
where M is a metal atom from the Periodic Table of the Elements and may be a Group 3 to 12 metal or from the lanthanide or actinide series of the Periodic Table of Elements, preferably M is a Group 4, 5 or 6 transition metal, more preferably M is a Group 4 transition metal, even more preferably M is zirconium, hafnium or titanium. The bulky ligands, LA and LB, are open, acyclic or fused ring(s) or ring system(s) and are any ancillary ligand system, including unsubstituted or substituted, cyclopentadienyl ligands or cyclopentadienyl-type ligands, heteroatom substituted and/or heteroatom containing cyclopentadienyl-type ligands. Non-limiting examples of bulky ligands include cyclopentadienyl ligands, cyclopentaphenanthreneyl ligands, indenyl ligands, benzindenyl ligands, fluorenyl ligands, octahydrofluorenyl ligands, cyclooctatetraendiyl ligands, cyclopentacyclododecene ligands, azenyl ligands, azulene ligands, pentalene ligands, phosphoyl ligands, phosphinimine (WO 99/40125), pyrrolyl ligands, pyrozolyl ligands, carbazolyl ligands, borabenzene ligands and the like, including hydrogenated versions thereof, for example tetrahydroindenyl ligands. In one embodiment, LA and LB may be any other ligand structure capable of xcex7-bonding to M, preferably xcex73-bonding to M and most preferably xcex75-bonding. In yet another embodiment, the atomic molecular weight (MW) of LA or LB exceeds 60 a.m.u., preferably greater than 65 a.m.u. In another embodiment, LA and LB may comprise one or more heteroatoms, for example, nitrogen, silicon, boron, germanium, sulfur and phosphorous, in combination with carbon atoms to form an open, acyclic, or preferably a fused, ring or ring system, for example, a hetero-cyclopentadienyl ancillary ligand. Other LA and Lb bulky ligands include but are not limited to bulky amides, phosphides, alkoxides, aryloxides, imides, carbolides, borollides, porphyrins, phthalocyanines, corrins and other polyazomacrocycles. Independently, each LA and LB may be the same or different type of bulky ligand that is bonded to M. In one embodiment of formula (III) only one of either LA or LB is present.
Independently, each LA and LB may be unsubstituted or substituted with a combination of substituent groups R. Non-limiting examples of substituent groups R include one or more from the group selected from hydrogen, or linear, branched alkyl radicals, or alkenyl radicals, alkynyl radicals, cycloalkyl radicals or aryl radicals, acyl radicals, aroyl radicals, alkoxy radicals, aryloxy radicals, alkylthio radicals, dialkylamino radicals, alkoxycarbonyl radicals, aryloxycarbonyl radicals, carbomoyl radicals, alkyl- or dialkyl-carbamoyl radicals, acyloxy radicals, acylamino radicals, aroylamino radicals, straight, branched or cyclic, alkylene radicals, or combination thereof. In a preferred embodiment, substituent groups R have up to 50 non-hydrogen atoms, preferably from 1 to 30 carbon, that can also be substituted with halogens or heteroatoms or the like. Non-limiting examples of alkyl substituents R include methyl, ethyl, propyl, butyl, pentyl, hexyl, cyclopentyl, cyclohexyl, benzyl or phenyl groups and the like, including all their isomers, for example tertiary butyl, isopropyl, and the like. Other hydrocarbyl radicals include fluoromethyl, fluroethyl, difluroethyl, iodopropyl, bromohexyl, chlorobenzyl and hydrocarbyl substituted organometalloid radicals including trimethylsilyl, trimethylgermyl, methyldiethylsilyl and the like; and halocarbyl-substituted organometalloid radicals including tris(trifluoromethyl)-silyl, methyl-bis(difluoromethyl)silyl, bromomethyldimethylgermyl and the like; and disubstitiuted boron radicals including dimethylboron for example; and disubstituted pnictogen radicals including dimethylamine, dimethylphosphine, diphenylamine, methylphenylphosphine, chalcogen radicals including methoxy, ethoxy, propoxy, phenoxy, methylsulfide and ethylsulfide. Non-hydrogen substituents R include the atoms carbon, silicon, boron, aluminum, nitrogen, phosphorous, oxygen, tin, sulfur, germanium and the like, including olefins such as but not limited to olefinically unsaturated substituents including vinyl-terminated ligands, for example but-3-enyl, prop-2-enyl, hex-5-enyl and the like. Also, at least two R groups, preferably two adjacent R groups, are joined to form a ring structure having from 3 to 30 atoms selected from carbon, nitrogen, oxygen, phosphorous, silicon, germanium, aluminum, boron or a combination thereof. Also, a substituent group R group such as 1-butanyl may form a carbon sigma bond to the metal M.
Other ligands may be bonded to the metal M, such as at least one leaving group Q. In one embodiment, Q is a monoanionic labile ligand having a sigma-bond to M. Depending on the oxidation state of the metal, the value for n is 0, 1 or 2 such that formula (III) above represents a neutral bulky ligand metallocene-type catalyst compound.
Non-limiting examples of Q ligands include weak bases such as amines, phosphines, ethers, carboxylates, dienes, hydrocarbyl radicals having from 1 to 20 carbon atoms, hydrides or halogens and the like or a combination thereof. In another embodiment, two or more Q""s form a part of a fused ring or ring system. Other examples of Q ligands include those substituents for R as described above and including cyclobutyl, cyclohexyl, heptyl, tolyl, trifluromethyl, tetramethylene, pentamethylene, methylidene, methyoxy, ethyoxy, propoxy, phenoxy, bis(N-methylanilide), dimethylamide, dimethylphosphide radicals and the like.
In one embodiment, the bulky ligand metallocene-type catalyst compounds of the invention include those of formula (III) where LA and LB are bridged to each other by at least one bridging group, A, such that the formula is represented by
LAALBMQnxe2x80x83xe2x80x83(IV) 
These bridged compounds represented by formula (IV) are known as bridged, bulky ligand metallocene-type catalyst compounds. LA, LB, M, Q and n are as defined above. Non-limiting examples of bridging group A include bridging groups containing at least one Group 13 to 16 atom, often referred to as a divalent moiety such as but not limited to at least one of a carbon, oxygen, nitrogen, silicon, aluminum, boron, germanium and tin atom or a combination thereof. Preferably bridging group A contains a carbon, silicon or germanium atom, most preferably A contains at least one silicon atom or at least one carbon atom. The bridging group A may also contain substituent groups R as defined above including halogens and iron. Non-limiting examples of bridging group A may be represented by Rxe2x80x22C, Rxe2x80x22Si, Rxe2x80x22Si Rxe2x80x22Si, Rxe2x80x22Ge, Rxe2x80x2P, where Rxe2x80x2 is independently, a radical group which is hydride, hydrocarbyl, substituted hydrocarbyl, halocarbyl, substituted halocarbyl, hydrocarbyl-substituted organometalloid, halocarbyl-substituted organometalloid, disubstituted boron, disubstituted pnictogen, substituted chalcogen, or halogen or two or more Rxe2x80x2 may be joined to form a ring or ring system. In one embodiment, the bridged, bulky ligand metallocene-type catalyst compounds of formula (IV) have two or more bridging groups A (EP 664 301 B1).
In one embodiment, the bulky ligand metallocene-type catalyst compounds are those where the R substituents on the bulky ligands LA and LB of formulas (III) and (IV) are substituted with the same or different number of substituents on each of the bulky ligands. In another embodiment, the bulky ligands LA and LB of formulas (III) and (IV) are different from each other.
Other bulky ligand metallocene-type catalyst compounds and catalyst systems useful in the invention may include those described in U.S. Pat. Nos. 5,064,802, 5,145,819, 5,149,819, 5,243,001, 5,239,022, 5,276,208, 5,296,434, 5,321,106, 5,329,031, 5,304,614, 5,677,401, 5,723,398, 5,753,578, 5,854,363, 5,856,547 5,858,903, 5,859,158, 5,900,517 and 5,939,503 and PCT publications WO 93/08221, WO 93/08199, WO 95/07140, WO 98/11144, WO 98/41530, WO 98/41529, WO 98/46650, WO 99/02540 and WO 99/14221 and European publications EP-A-0 578 838, EP-A-0 638 595, EP-B-0 513 380, EP-A1-0 816 372, EP-A2-0 839 834, EP-B1-0 632 819, EP-B1-0 748 821 and EP-B1-0 757 996, all of which are herein fully incorporated by reference.
In one embodiment, bulky ligand metallocene-type catalysts compounds useful in the invention include bridged heteroatom, mono-bulky ligand metallocene-type compounds. These types of catalysts and catalyst systems are described in, for example, PCT publication WO 92/00333, WO 94/07928, WO 91/04257, WO 94/03506, WO96/00244, WO 97/15602 and WO 99/20637 and U.S. Pat. Nos. 5,057,475, 5,096,867, 5,055,438, 5,198,401, 5,227,440 and 5,264,405 and European publication EP-A-0 420 436, all of which are herein fully incorporated by reference.
In this embodiment, the bulky ligand metallocene-type catalyst compound is represented by the formula:
LCAJMQnxe2x80x83xe2x80x83(V) 
where M is a Group 3 to 16 metal atom or a metal selected from the Group of actinides and lanthanides of the Periodic Table of Elements, preferably M is a Group 4 to 12 transition metal, and more preferably M is a Group 4, 5 or 6 transition metal, and most preferably M is a Group 4 transition metal in any oxidation state, especially titanium; LC is a substituted or unsubstituted bulky ligand bonded to M; J is bonded to M; A is bonded to M and J; J is a heteroatom ancillary ligand; and A is a bridging group; Q is a univalent anionic ligand; and n is the integer 0, 1 or 2. In formula (V) above, LC, A and J form a fused ring system. In an embodiment, LCof formula (V) is as defined above for LA, A, M and Q of formula (V) are as defined above in formula (III).
In formula (V) J is a heteroatom containing ligand in which J is an element with a coordination number of three from Group 15 or an element with a coordination number of two from Group 16 of the Periodic Table of Elements. Preferably J contains a nitrogen, phosphorus, oxygen or sulfur atom with nitrogen being most preferred.
In an embodiment of the invention, the bulky ligand metallocene-type catalyst compounds are heterocyclic ligand complexes where the bulky ligands, the ring(s) or ring system(s), include one or more heteroatoms or a combination thereof. Non-limiting examples of heteroatoms include a Group 13 to 16 element, preferably nitrogen, boron, sulfur, oxygen, aluminum, silicon, phosphorous and tin. Examples of these bulky ligand metallocene-type catalyst compounds are described in WO 96/33202, WO 96/34021, WO 97/17379 and WO 98/22486 and EP-A1-0 874 005 and U.S. Pat. Nos. 5,637,660, 5,539,124, 5,554,775, 5,756,611, 5,233,049, 5,744,417, and 5,856,258 all of which are herein incorporated by reference.
In one embodiment, the bulky ligand metallocene-type catalyst compounds are those complexes known as transition metal catalysts based on bidentate ligands containing pyridine or quinoline moieties, such as those described in U.S. application Ser. No. 09/103,620 filed Jun. 23, 1998, which is herein incorporated by reference. In another embodiment, the bulky ligand metallocene-type catalyst compounds are those described in PCT publications WO 99/01481 and WO 98/42664, which are fully incorporated herein by reference.
In a preferred embodiment, the bulky ligand type metallocene-type catalyst compound is a complex of a metal, preferably a transition metal, a bulky ligand, preferably a substituted or unsubstituted pi-bonded ligand, and one or more heteroallyl moieties, such as those described in U.S. Pat. Nos. 5,527,752 and 5,747,406 and EP-B1-0 735 057, all of which are herein fully incorporated by reference.
In a particularly preferred embodiment, the other metal compound or second metal compound is the bulky ligand metallocene-type catalyst compound is represented by the formula:
LDMQ2(YZ)Xnxe2x80x83xe2x80x83(VI) 
where M is a Group 3 to 16 metal, preferably a Group 4 to 12 transition metal, and most preferably a Group 4, 5 or 6 transition metal; LD is a bulky ligand that is bonded to M; each Q is independently bonded to M and Q2(YZ) forms a ligand, preferably a unicharged polydentate ligand; A or Q is a univalent anionic ligand also bonded to M; X is a univalent anionic group when n is 2 or X is a divalent anionic group when n is 1; n is 1 or 2.
In formula (VI), L and M are as defined above for formula (III). Q is as defined above for formula (III), preferably Q is selected from the group consisting of xe2x80x94Oxe2x80x94, xe2x80x94NRxe2x80x94, xe2x80x94CR2xe2x80x94 and xe2x80x94Sxe2x80x94; Y is either C or S; Z is selected from the group consisting of xe2x80x94OR, xe2x80x94NR2, xe2x80x94CR3, xe2x80x94SR, xe2x80x94SiR3, xe2x80x94PR2, xe2x80x94H, and substituted or unsubstituted aryl groups, with the proviso that when Q is xe2x80x94NRxe2x80x94 then Z is selected from one of the group consisting of xe2x80x94OR, xe2x80x94NR2, xe2x80x94SR, xe2x80x94SiR3, xe2x80x94PR2 and xe2x80x94H; R is selected from a group containing carbon, silicon, nitrogen, oxygen, and/or phosphorus, preferably where R is a hydrocarbon group containing from 1 to 20 carbon atoms, most preferably an alkyl, cycloalkyl, or an aryl group; n is an integer from 1 to 4, preferably 1 or 2; X is a univalent anionic group when n is 2 or X is a divalent anionic group when n is 1; preferably X is a carbamate, carboxylate, or other heteroallyl moiety described by the Q, Y and Z combination.
In a particularly preferred embodiment the bulky ligand metallocene-type compound is represented by the formula: 
Activator and Activation Methods
The metal compounds described herein are preferably combined with one or more activators to form an olefin polymerization catalyst system.
For the purposes of this patent specification and appended claims, the term xe2x80x9cactivatorxe2x80x9d is defined to be any compound or component or method which can activate any of the Group 15 containing metal compounds and/or the bulky ligand metallocene-type catalyst compounds of the invention as described above. Non-limiting activators, for example may include a Lewis acid or a non-coordinating ionic activator or ionizing activator or any other compound including Lewis bases, aluminum alkyls, conventional-type cocatalysts and combinations thereof that can convert a neutral bulky ligand metallocene-type catalyst compound or Group 15 containing metal compound to a catalytically active Group 15 containing metal compound or bulky ligand metallocene-type cation. It is within the scope of this invention to use alumoxane or modified alumoxane as an activator, and/or to also use ionizing activators, neutral or ionic, such as tri (n-butyl) ammonium tetrakis (pentafluorophenyl) boron, a trisperfluorophenyl boron metalloid precursor or a trisperfluoronaphtyl boron metalloid precursor, polyhalogenated heteroborane anions (WO 98/43983) or combination thereof, that would ionize the neutral bulky ligand metallocene-type catalyst and/or the Group 15 containing metal compound.
In one embodiment, an activation method using ionizing ionic compounds not containing an active proton but capable of producing a Group 15 containing metal compound cation or bulky ligand metallocene-type catalyst cation and their non-coordinating anion are also contemplated, and are described in EP-A-0 426 637, EP-A-0 573 403 and U.S. Pat. No. 5,387,568, which are all herein incorporated by reference.
There are a variety of methods for preparing alumoxane and modified alumoxanes, non-limiting examples of which are described in U.S. Pat. Nos. 4,665,208, 4,952,540, 5,091,352, 5,206,199, 5,204,419, 4,874,734, 4,924,018, 4,908,463, 4,968,827, 5,308,815, 5,329,032, 5,248,801, 5,235,081, 5,157,137, 5,103,031, 5,391,793, 5,391,529, 5,693,838, 5,731,253, 5,731,451, 5,744,656, 5,847,177, 5,854,166, 5,856,256 and 5,939,346 and European publications EP-A-0 561 476, EP-B1-0 279 586, EP-A-0 594-218 and EP-B1-0 586 665, and PCT publication WO 94/10180, all of which are herein fully incorporated by reference.
Organoaluminum compounds useful as activators include trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum and the like.
Ionizing compounds may contain an active proton, or some other cation associated with but not coordinated to or only loosely coordinated to the remaining ion of the ionizing compound. Such compounds and the like are described in European publications EP-A-0 570 982, EP-A-0 520 732, EP-A-0 495 375, EP-B1-0 500 944, EP-A-0 277 003 and EP-A-0 277 004, and U.S. Pat. Nos. 5,153,157, 5,198,401, 5,066,741, 5,206,197, 5,241,025, 5,384,299 and 5,502,124 and U.S. patent application Ser. No. 08/285,380, filed Aug. 3, 1994, all of which are herein fully incorporated by reference.
Other activators include those described in PCT publication WO 98/07515 such as tris (2,2xe2x80x2,2xe2x80x3-nonafluorobiphenyl) fluoroaluminate, which publication is fully incorporated herein by reference. Combinations of activators are also contemplated by the invention, for example, alumoxanes and ionizing activators in combinations, see for example, EP-B1 0 573 120, PCT publications WO 94/07928 and WO 95/14044 and U.S. Pat. Nos. 5,153,157 and 5,453,410 all of which are herein fully incorporated by reference. WO 98/09996 incorporated herein by reference describes activating bulky ligand metallocene-type catalyst compounds with perchlorates, periodates and iodates including their hydrates. WO 98/30602 and WO 98/30603 incorporated by reference describe the use of lithium (2,2xe2x80x2-bisphenyl-ditrimethylsilicate).4THF as an activator for a bulky ligand metallocene-type catalyst compound. WO 99/18135 incorporated herein by reference describes the use of organo-boron-aluminum acitivators. EP-B1-0 781 299 describes using a silylium salt in combination with a non-coordinating compatible anion. Also, methods of activation such as using radiation (see EP-B1-0 615 981 herein incorporated by reference), electro-chemical oxidation, and the like are also contemplated as activating methods for the purposes of rendering the neutral bulky ligand metallocene-type catalyst compound or precursor to a bulky ligand metallocene-type cation capable of polymerizing olefins. Other activators or methods for activating a bulky ligand metallocene-type catalyst compound are described in for example, U.S. Pat. Nos. 5,849,852, 5,859,653 and 5,869,723 and WO 98/32775, WO 99/42467 (dioctadecylmethylammonium-bis(tris(pentafluorophenyl)borane) benzimidazolide), which are herein incorporated by reference.
It is also within the scope of this invention that the above described Group 15 containing metal compounds and bulky ligand metallocene-type catalyst compounds can be combined with one or more of the catalyst compounds represented by formulas (III) through (VI) with one or more activators or activation methods described above.
It is also contemplated that any one of the bulky ligand metallocene-type catalyst compounds of the invention have at least one fluoride or fluorine containing leaving group as described in U.S. application Ser. No. 09/191,916 filed Nov. 13, 1998.
In a preferred embodiment modified alumoxanes are combined with the first and second metal compounds of the invention to form a catalyst system. In a preferred embodiment MMAO3A (modified methyl alumoxane in heptane, commercially available from Akzo Chemicals, Inc., Holland, under the trade name Modified Methylalumoxane type 3A, see for example those aluminoxanes disclosed in U.S. Pat. No. 5,041,584, which is herein incorporated by reference) is combined with the first and second metal compounds to form a catalyst system.
The first and second metal compounds may be combined at molar ratios of 1:1000 to 1000:1, preferably 1:99 to 99:1, preferably 10:90 to 90:10, more preferably 20:80 to 80:20, more preferably 30:70 to 70:30, more preferably 40:60 to 60:40. The particular ratio chosen will depend on the end product desired and/or the method of activation
In a particular embodiment, when using, the metal compounds represented by Formula 1 and Formula 2, where both are activated with the same activator, the preferred weight percents, based upon the weight of the two metal compounds, but not the activator or any support, are 10 to 95 weight % compound of formula 1 and 5 to 90 weight % compound of formula 2, preferably 50 to 90 weight % compound of Formula 1 and 10 to 50 weight % compound of formula 2, more preferably 60 to 80 weight % compound of formula 1 to 40 to 20 weight % compound of formula 2. In a particularly preferred embodiment the compound of Formula 2 is activated with methylalumoxane, then combined with the compound of Formula 2, then injected in the reactor.
In one particular embodiment, when using Compound I and indenyl zirconium tris-pivalate where both are activated with the same activator, the preferred weight percents, based upon the weight of the two catalysts, but not the activator or any support, are 10 to 95 weight % Compound I and 5 to 90 weight % indenyl zirconium tris-pivalate, preferably 50 to 90 weight % Compound I and 10 to 50 weight % indenyl zirconium tris-pivalate, more preferably 60-80 weight % Compound I to 40 to 20 weight % indenyl zirconium tris-pivalate. In a particularly preferred embodiment the indenyl zirconium tris-pivalate is activated with methylalumoxane, then combined with Compound I, then injected in the reactor.
In general the combined metal compounds and the activator are combined in ratios of about 1000:1 to about 0.5:1. In a preferred embodiment the metal compounds and the activator are combined in a ratio of about 300:1 to about 1:1, preferably about 150:1 to about 1:1, for boranes, borates, aluminates, etc. the ratio is preferably about 1:1 to about 10:1 and for alkyl aluminum compounds (such as diethylaluminum chloride combined with water) the ratio is preferably about 0.5:1 to about 10:1.
Conventional-Type Catalyst Systems Combinable with Formulae I and II
The mixed catalyst composition of the present invention may alternately include the Group 15 containing metal compound, as described above, and a conventional-type transition catalyst.
Conventional-type transition metal catalysts are those traditional Ziegler-Natta, vanadium and Phillips-type catalysts well known in the art. Such as, for example Ziegler-Natta catalysts as described in Ziegler-Natta Catalysts and Polymerizations, John Boor, Academic Press, New York, 1979. Examples of conventional-type transition metal catalysts are also discussed in U.S. Pat. Nos. 4,115,639, 4,077,904, 4,482,687, 4,564,605, 4,721,763, 4,879,359 and 4,960,741 all of which are herein fully incorporated by reference. The conventional-type transition metal catalyst compounds that may be used in the present invention include transition metal compounds from Groups 3 to 17, preferably 4 to 12, more preferably 4 to 6 of the Periodic Table of Elements.
These conventional-type transition metal catalysts may be represented by the formula: MRx, where M is a metal from Groups 3 to 17, preferably Group 4 to 6, more preferably Group 4, most preferably titanium; R is a halogen or a hydrocarbyloxy group; and x is the oxidation state of the metal M. Non-limiting examples of R include alkoxy, phenoxy, bromide, chloride and fluoride. Non-limiting examples of conventional-type transition metal catalysts where M is titanium include TiCl4, TiBr4, Ti(OC2H5)3Cl, Ti(OC2H5)Cl3, Ti(OC4H9)3Cl, Ti(OC3H7)2Cl2, Ti(OC2H5)2Br2, TiCl3.⅓AlCl3 and Ti(OC12H25)Cl3.
Conventional-type transition metal catalyst compounds based on magnesium/titanium electron-donor complexes that are useful in the invention are described in, for example, U.S. Pat. Nos. 4,302,565 and 4,302,566, which are herein fully incorporate by reference. The MgTiCl6 (ethyl acetate)4 derivative is particularly preferred.
British Patent Application 2,105,355 and U.S. Pat. No. 5,317,036, herein incorporated by reference, describes various conventional-type vanadium catalyst compounds. Non-limiting examples of conventional-type vanadium catalyst compounds include vanadyl trihalide, alkoxy halides and alkoxides such as VOCl3, VOCl2(OBu) where Bu=butyl and VO(OC2H5)3; vanadium tetra-halide and vanadium alkoxy halides such as VCl4 and VCl3(OBu); vanadium and vanadyl acetyl acetonates and chloroacetyl acetonates such as V(AcAc)3 and VOCl2(AcAc) where (AcAc) is an acetyl acetonate. The preferred conventional-type vanadium catalyst compounds are VOCl3, VCl4 and VOCl2-OR where R is a hydrocarbon radical, preferably a C1 to C10 aliphatic or aromatic hydrocarbon radical such as ethyl, phenyl, isopropyl, butyl, propyl, n-butyl, iso-butyl, tertiary-butyl, hexyl, cyclohexyl, naphthyl, etc., and vanadium acetyl acetonates.
Conventional-type chromium catalyst compounds, often referred to as Phillips-type catalysts, suitable for use in the present invention include CrO3, chromocene, silyl chromate, chromyl chloride (CrO2Cl2), chromium-2-ethyl-hexanoate, chromium acetylacetonate (Cr(AcAc)3), and the like. Non-limiting examples are disclosed in U.S. Pat. Nos. 3,709,853, 3,709,954, 3,231,550, 3,242,099 and 4,077,904, which are herein fully incorporated by reference.
Still other conventional-type transition metal catalyst compounds and catalyst systems suitable for use in the present invention are disclosed in U.S. Pat. Nos. 4,124,532, 4,302,565, 4,302,566, 4,376,062, 4,379,758, 5,066,737, 5,763,723, 5,849,655, 5,852,144, 5,854,164 and 5,869,585 and published EP-A2 0 416 815 A2 and EP-A1 0 420 436, which are all herein incorporated by reference.
Other catalysts may include cationic catalysts such as AlCl3, and other cobalt, iron, nickel and palladium catalysts well known in the art. See for example U.S. Pat. Nos. 3,487,112, 4,472,559, 4,182,814 and 4,689,437 all of which are incorporated herein by reference.
Typically, these conventional-type transition metal catalyst compounds excluding some conventional-type chromium catalyst compounds are activated with one or more of the conventional-type cocatalysts described below. Also conventional type transition metal catalysts can be activated using the activators described above in this patent specification as appreciated by one in the art.
Conventional-type cocatalyst compounds for the above conventional-type transition metal catalyst compounds may be represented by the formula M3M4vX2cR3b-c, wherein M3 is a metal from Group 1 to 3 and 12 to 13 of the Periodic Table of Elements; M4 is a metal of Group 1 of the Periodic Table of Elements; v is a number from 0 to 1; each X2 is any halogen; c is a number from 0 to 3; each R3 is a monovalent hydrocarbon radical or hydrogen; b is a number from 1 to 4; and wherein b minus c is at least 1. Other conventional-type organometallic cocatalyst compounds for the above conventional-type transition metal catalysts have the formula M3R3k, where M3 is a Group IA, IIA, IIB or IIIA metal, such as lithium, sodium, beryllium, barium, boron, aluminum, zinc, cadmium, and gallium; k equals 1, 2 or 3 depending upon the valency of M3 which valency in turn normally depends upon the particular Group to which M3 belongs; and each R3 may be any monovalent hydrocarbon radical.
Non-limiting examples of conventional-type organometallic cocatalyst compounds useful with the conventional-type catalyst compounds described above include methyllithium, butyllithium, dihexylmercury, butylmagnesium, diethylcadmium, benzylpotassium, diethylzinc, tri-n-butylaluminum, diisobutyl ethylboron, diethylcadmium, di-n-butylzinc and tri-n-amylboron, and, in particular, the aluminum alkyls, such as tri-hexyl-aluminum, triethylaluminum, trimethylaluminum, and tri-isobutylaluminum. Other conventional-type cocatalyst compounds include mono-organohalides and hydrides of Group 2 metals, and mono- or di-organohalides and hydrides of Group 3 and 13 metals. Non-limiting examples of such conventional-type cocatalyst compounds include di-isobutylaluminum bromide, isobutylboron dichloride, methyl magnesium chloride, ethylberyllium chloride, ethylcalcium bromide, di-isobutylaluminum hydride, methylcadmium hydride, diethylboron hydride, hexylberyllium hydride, dipropylboron hydride, octylmagnesium hydride, butylzinc hydride, dichloroboron hydride, di-bromo-aluminum hydride and bromocadmium hydride. Conventional-type organometallic cocatalyst compounds are known to those in the art and a more complete discussion of these compounds may be found in U.S. Pat. Nos. 3,221,002 and 5,093,415, which are herein fully incorporated by reference.
Polymerization Process
The metal compounds, mixed metal compounds and catalyst systems described above are suitable for use in any polymerization process, including solution, gas or slurry processes or a combination thereof. The polymerization process is preferably a gas or slurry phase process and more preferably utilizes a single reactor, and most preferably a single gas phase reactor.
In a preferred embodiment, the catalyst system consists of the metal compounds (catalyst) and or the activator (cocatalyst) which are preferably introduced into the reactor in solution. Solutions of the metal compounds are prepared by taking the catalyst and dissolving it in any suitable solvent such as an alkane, toluene, xylene, etc. The solvent may first be purified in order to remove any poisons, which may affect the catalyst activity, including any trace water and/or oxygenated compounds. Purification of the solvent may be accomplished by using activated alumina and activated supported copper catalyst. The catalyst is preferably completely dissolved into the solution to form a homogeneous solution. Both catalysts may be dissolved into the same solvent, if desired. Once the catalysts are in solution, they may be stored indefinitely until use.
For polymerization, it preferred that the catalyst is combined with an activator prior to introduction into the reactor. Additionally, other solvents and reactants can be added to the catalyst solutions (on-line or off-line), to the activator (on-line or off-line), or to the activated catalyst or catalysts. See U.S. Pat. Nos. 5,317,036 and 5,693,727, EP-A-0 593 083, and WO 97/46599 which are fully incorporated herein by reference, that describe solution feed systems to a reactor. There are many different configurations which are possible to combine the catalysts and activator.
The catalyst system, the metal compounds and or the activator are preferably introduced into the reactor in one or more solutions. The metal compounds may be activated independently, in series or together. In one embodiment a solution of the two activated metal compounds in an alkane such as pentane, hexane, toluene, isopentane or the like is introduced into a gas phase or slurry phase reactor. In another embodiment the catalysts system or the components can be introduced into the reactor in a suspension or an emulsion. In one embodiment, the second metal compound is contacted with the activator, such as modified methylalumoxane, in a solvent and just before the solution is fed into a gas, slurry or solution phase reactor. A solution of the Group 15 containing metal compound is combined with a solution of the second compound and the activator and then introduced into the reactor.
In the following illustrations, A refers to a catalyst or mixture of catalysts, and B refers to a different catalyst or mixture of catalysts. The mixtures of catalysts in A and B can be the same catalysts, just in different ratios. Further, it is noted that additional solvents or inert gases may be added at many locations.
Illustration 1: A and B plus the activator are mixed off-line and then fed to the reactor.
Illustration 2: A and B are mixed off-line. Activator is added in-line and then fed to the reactor.
Illustration 3: A or B is contacted with the activator (off-line) and then either A or B is added in-line before entering the reactor.
Illustration 4: A or B is contacted with the activator (on-line) and then either A or B is added in-line before entering the reactor.
Illustration 5: A and B are each contacted with the activator off-line. Then A and activator and B and activator are contacted in line before entering the reactor.
Illustration 6: A and B are each contacted with the activator in-line. Then A and activator and B and activator are contacted in-line before entering the reactor. (This is a preferred configuration since the ratio of A to B and the ratio of activator to A and the ratio of activator to B can be controlled independently.)
Illustration 7: In this example, A or B is contacted with the activator (on-line) while a separate solution of either A or B is contacted with activator off-line. Then both stream of A or B and activator are contacted in-line before entering the reactor.
Illustration 8: A is contacted on-line with B. Then, an activator is fed to in-line to the A and B mixture.
Illustration9: A is activated with activator off-line. Then A and activator is contacted on-line with B. Then, an activator is fed to in-line to the A and B and activator mixture.
In one embodiment, this invention is directed toward the polymerization or copolymerization reactions involving the polymerization of one or more monomers having from 2 to 30 carbon atoms, preferably 2 to 12 carbon atoms, and more preferably 2 to 8 carbon atoms. The invention is particularly well suited to the copolymerization reactions involving the polymerization of one or more olefin monomers of ethylene, propylene, butene-1, pentene-1,4-methyl-pentene-1, hexene-1, octene-1, decene-1,3-methyl-pentene-1,3,5,5-trimethyl-hexene-1 and cyclic olefins or a combination thereof. Other monomers can include vinyl monomers, diolefins such as dienes, polyenes, norbornene, norbornadiene monomers. Preferably a copolymer of ethylene is produced, where the comonomer is at least one alpha-olefin having from 4 to 15 carbon atoms, preferably from 4 to 12 carbon atoms, more preferably from 4 to 8 carbon atoms and most preferably from 4 to 7 carbon atoms. In an alternate embodiment, the geminally disubstituted olefins disclosed in WO 98/37109 may be polymerized or copolymerized using the invention herein described.
In another embodiment ethylene or propylene is polymerized with at least two different comonomers to form a terpolymer. The preferred comonomers are a combination of alpha-olefin monomers having 4 to 10 carbon atoms, more preferably 4 to 8 carbon atoms, optionally with at least one diene monomer. The preferred terpolymers include the combinations such as ethylene/butene-1/hexene-1, ethylene/propylene/butene-1, propylene/ethylene/hexene-1, ethylene/propylene/norbornene and the like.
In a particularly preferred embodiment the process of the invention relates to the polymerization of ethylene and at least one comonomer having from 4 to 8 carbon atoms, preferably 4 to 7 carbon atoms. Particularly, the comonomers are butene-1, 4-methyl-pentene-1, hexene-1 and octene-1, the most preferred being hexene-1 and/or butene-1.
Typically in a gas phase polymerization process a continuous cycle is employed where in one part of the cycle of a reactor system, a cycling gas stream, otherwise known as a recycle stream or fluidizing medium, is heated in the reactor by the heat of polymerization. This heat is removed from the recycle composition in another part of the cycle by a cooling system external to the reactor. Generally, in a gas fluidized bed process for producing polymers, a gaseous stream containing one or more monomers is continuously cycled through a fluidized bed in the presence of a catalyst under reactive conditions. The gaseous stream is withdrawn from the fluidized bed and recycled back into the reactor. Simultaneously, polymer product is withdrawn from the reactor and fresh monomer is added to replace the polymerized monomer. (See for example U.S. Pat. Nos. 4,543,399, 4,588,790, 5,028,670, 5,317,036, 5,352,749, 5,405,922, 5,436,304, 5,453,471, 5,462,999, 5,616,661 and 5,668,228 all of which are fully incorporated herein by reference.)
The reactor pressure in a gas phase process may vary from about 10 psig (69 kPa) to about 500 psig (3448 kPa), preferably in the range of from about 100 psig (690 kPa) to about 400 psig (2759 kPa), preferably in the range of from about 200 psig (1379 kPa) to about 400 psig (2759 kPa), more preferably in the range of from about 250 psig (1724 kPa) to about 350 psig (2414 kPa).
The reactor temperature in the gas phase process may vary from about 30xc2x0 C. to about 120xc2x0 C., preferably from about 60xc2x0 C. to about 115xc2x0 C., more preferably in the range of from about 75xc2x0 C. to 110xc2x0 C., and most preferably in the range of from about 85xc2x0 C. to about 110xc2x0 C. Altering the polymerization temperature can also be used as a tool to alter the final polymer product properties.
The productivity of the catalyst or catalyst system is influenced by the main monomer partial pressure. The preferred mole percent of the main monomer, ethylene or propylene, preferably ethylene, is from about 25 to 90 mole percent and the monomer partial pressure is in the range of from about 75 psia (517 kPa) to about 300 psia (2069 kPa), which are typical conditions in a gas phase polymerization process. In one embodiment the ethylene partial pressure is about 220 to 240 psi (1517-1653 kPa). In another embodiment the molar ratio of hexene to ethylene ins the reactor is 0.03:1 to 0.08:1.
In a preferred embodiment, the reactor utilized in the present invention and the process of the invention produce greater than 500 lbs of polymer per hour (227 Kg/hr) to about 200,000 lbs/hr (90,900 Kg/hr) or higher of polymer, preferably greater than 1000 lbs/hr (455 Kg/hr), more preferably greater than 10,000 lbs/hr (4540 Kg/hr), even more preferably greater than 25,000 lbs/hr (11,300 Kg/hr), still more preferably greater than 35,000 lbs/hr (15,900 Kg/hr), still even more preferably greater than 50,000 lbs/hr (22,700 Kg/hr) and most preferably greater than 65,000 lbs/hr (29,000 Kg/hr) to greater than 100,000 lbs/hr (45,500 Kg/hr).
Other gas phase processes contemplated by the process of the invention include those described in U.S. Pat. Nos. 5,627,242, 5,665,818 and 5,677,375, and European publications EP-A-0 794 200, EP-A-0 802 202 and EP-B-634 421 all of which are herein fully incorporated by reference.
A slurry polymerization process generally uses pressures in the range of from about 1 to about 50 atmospheres and even greater and temperatures in the range of 0xc2x0 C. to about 120xc2x0 C. In a slurry polymerization, a suspension of solid, particulate polymer is formed in a liquid polymerization diluent medium to which ethylene and comonomers and often hydrogen along with catalyst are added. The suspension including diluent is intermittently or continuously removed from the reactor where the volatile components are separated from the polymer and recycled, optionally after a distillation, to the reactor. The liquid diluent employed in the polymerization medium is typically an alkane having from 3 to 7 carbon atoms, preferably a branched alkane. The medium employed should be liquid under the conditions of polymerization and relatively inert. When a propane medium is used the process must be operated above the reaction diluent critical temperature and pressure. Preferably, a hexane or an isobutane medium is employed.
In one embodiment, a preferred polymerization technique of the invention is referred to as a particle form polymerization, or a slurry process where the temperature is kept below the temperature at which the polymer goes into solution. Such technique is well known in the art, and described in for instance U.S. Pat. No. 3,248,179 which is fully incorporated herein by reference. The preferred temperature in the particle form process is within the range of about 185xc2x0 F. (85xc2x0 C.) to about 230xc2x0 F. (110xc2x0 C.). Two preferred polymerization methods for the slurry process are those employing a loop reactor and those utilizing a plurality of stirred reactors in series, parallel, or combinations thereof. Non-limiting examples of slurry processes include continuous loop or stirred tank processes. Also, other examples of slurry processes are described in U.S. Pat. No. 4,613,484, which is herein fully incorporated by reference.
In another embodiment, the slurry process is carried out continuously in a loop reactor. The catalyst as a solution, as a suspension, as an emulsion, as a slurry in isobutane or as a dry free flowing powder is injected regularly to the reactor loop, which is itself filled with circulating slurry of growing polymer particles in a diluent of isobutane containing monomer and comonomer. Hydrogen, optionally, may be added as a molecular weight control. The reactor is maintained at pressure of about 525 psig to 625 psig (3620 kPa to 4309 kPa) and at a temperature in the range of about 140xc2x0 F. to about 220xc2x0 F. (about 60xc2x0 C. to about 104xc2x0 C.) depending on the desired polymer density. Reaction heat is removed through the loop wall since much of the reactor is in the form of a double-jacketed pipe. The slurry is allowed to exit the reactor at regular intervals or continuously to a heated low pressure flash vessel, rotary dryer and a nitrogen purge column in sequence for removal of the isobutane diluent and all unreacted monomer and comonomers. The resulting hydrocarbon free powder is then compounded for use in various applications.
In an embodiment the reactor used in the slurry process of the invention is capable of and the process of the invention is producing greater than 2000 lbs of polymer per hour (907 Kg/hr), more preferably greater than 5000 lbs/hr (2268 Kg/hr), and most preferably greater than 10,000 lbs/hr (4540 Kg/hr). In another embodiment the slurry reactor used in the process of the invention is producing greater than 15,000 lbs of polymer per hour (6804 Kg/hr), preferably greater than 25,000 lbs/hr (11,340 Kg/hr) to about 100,000 lbs/hr (45,500 Kg/hr).
In another embodiment in the slurry process of the invention the total reactor pressure is in the range of from 400 psig (2758 kPa) to 800 psig (5516 kPa), preferably 450 psig (3103 kPa) to about 700 psig (4827 kPa), more preferably 500 psig (3448 kPa) to about 650 psig (4482 kPa), most preferably from about 525 psig (3620 kPa) to 625 psig (4309 kPa).
In yet another embodiment in the slurry process of the invention the concentration of ethylene in the reactor liquid medium is in the range of from about 1 to 10 weight percent, preferably from about 2 to about 7 weight percent, more preferably from about 2.5 to about 6 weight percent, most preferably from about 3 to about 6 weight percent.
A preferred process of the invention is where the process, preferably a slurry or gas phase process is operated in the absence of or essentially free of any scavengers, such as triethylaluminum, trimethylaluminum, tri-isobutylaluminum and tri-n-hexylaluminum and diethyl aluminum chloride, dibutyl zinc and the like. This preferred process is described in PCT publication WO 96/08520 and U.S. Pat. No. 5,712,352, which are herein fully incorporated by reference.
In a preferred embodiment of the invention, a slurry of an aluminum distearate in mineral oil is introduced into the reactor, separately or with the first and or second metal complex and/or with an activator, from the metal compounds and or the activators. More information on using aluminum stearate type additives may be found in U.S. application Ser. No. 09/113,261 filed Jul. 10, 1998, which is incorporated by reference herein.
In an embodiment, if the second metal compound and Group 15 metal compound of the catalyst system are introduced to the reactor in series, it is preferably that the second metal compound is added and/or activated first and that the Group 15 metal compound is added and/or activated second.
In another embodiment, the residence time of the catalyst composition is between about 3 to about 6 hours and preferably between about 3.5 and about 5 hours.
In an embodiment, the mole ratio of comonomer to ethylene, Cx/C2, where Cxis the amount of comonomer and C2 is the amount of ethylene is between about 0.001 to 0.0100 and more preferably between about 0.002 to 0.008.
The melt index (and other properties) of the polymer produced may be changed by manipulating hydrogen concentration in the polymerization system by:
1) changing the amount of the first catalyst in the polymerization system, and/or
2) changing the amount of the second catalyst in the polymerization system, and/or
3) adding hydrogen to the polymerization process; and/or
4) changing the amount of liquid and/or gas that is withdrawn and/or purged from the process; and/or
5) changing the amount and/or composition of a recovered liquid and/or recovered gas returned to the polymerization process, said recovered liquid or recovered gas being recovered from polymer discharged from the polymerization process; and/or
6) using a hydrogenation catalyst in the polymerization process; and/or
7) changing the polymerization temperature; and/or
8) changing the ethylene partial pressure in the polymerization process; and/or
9) changing the ethylene to hexene ratio in the polymerization process; and/or
10) changing the activator to transition metal ratio in the activation sequence.
The hydrogen concentration in the reactor is about 100 to 5000 ppm, preferably 200 to 2000 ppm, more preferably 250 to 1900 ppm, more preferably 300 to 1800 ppm, and more preferably 350 to 1700 ppm, more preferably 400 to 1600 ppm, more preferably 500 to 1500 ppm, more preferably 500 to 1400 ppm, more preferably 500 to 1200 ppm, more preferably 600 to 1200 ppm, preferably 700 to 1100 ppm, and more preferably 800 to 1000 ppm. The hydrogen concentration in the reactor being inversely proportional to the polymer""s weight average molecular weight (MW).
The catalyst and/or the activator may be placed on, deposited on, contacted with, incorporated within, adsorbed, or absorbed in a support. Typically the support is any of the solid, porous supports, including microporous supports. Typical support materials include talc; inorganic oxides such as silica, magnesium chloride, alumina, silica-alumina; polymeric supports such as polyethylene, polypropylene, polystyrene, cross-linked polystyrene; and the like. Preferably the support is used in finely divided form. Prior to use the support is preferably partially or completely dehydrated. The dehydration may be done physically by calcining or by chemically converting all or part of the active hydroxyls. For more information on how to support catalysts, see U.S. Pat. No. 4,808,561 which discloses how to support a metallocene catalyst system. In addition, there are various other techniques of supporting catalysts as are well known in the art. Methods for supporting the Group 15 metal compound of the invention are described in U.S. application Ser. No. 09/312,878, filed May 17, 1999 which is herein incorporated by reference.
Polymer of the Invention
The new polymers produced by the process of the present invention may be used in a wide variety of products and end use applications. Preferably the new polymers include polyethylene, and even more preferably include bimodal polyethylene produced in a single reactor. In addition to bimodal polymers, it is not beyond the scope of the present application to produce a unimodal or multi-modal polymer.
The Group 15 containing metal compound, when used alone, produces a high weight average molecular weight Mw polymer (such as for example above 100,000, preferably above 150,000, preferably above 200,000, preferably above 250,000, more preferably above 300,000). The second metal compound, when used alone, produces a low molecular weight polymer (such as for example below 80,000, preferably below 70,000, preferably below 60,000, more preferably below 50,000, more preferably below 40,000, more preferably below 30,000, more preferably below 20,000 and above 5,000, more preferably below 20,000 and above 10,000).
The polyolefins, particularly polyethylenes, produced by the present invention, have a density of 0.89 to 0.97 g/cm3. Preferably, polyethylenes having a density of 0.910 to 0.965 g/cm3, more preferably 0.915 to 0.960 g/cm3, and even more preferably 0.920 to 0.955 g/cm3 can be produced. In some embodiments, a density of 0.915 to 0.940 g/cm3 would be preferred, in other embodiments densities of 0.930 to 0.970 g/cm3 are preferred.
In a preferred embodiment, the polyolefin recovered typically has a melt index I2 (as measured by ASTM D-1238, Condition E at 190xc2x0 C.) of about 0.01 to 1000 dg/min or less. In a preferred embodiment, the polyolefin is ethylene homopolymer or copolymer. In a preferred embodiment for certain applications, such as films, pipes, molded articles and the like, a melt index of 10 dg/min or less is preferred. For some films and molded articles, a melt index of 1 dg/min or less is preferred. Polyethylene having a I2 between 0.01 and 10 dg/min is preferred.
In a preferred embodiment the polymer produced herein has an I21 (as measured by ASTM-D-1238-F, at 190xc2x0 C.) of 0.1 to 10 dg/min, preferably 0.2 to 7.5 dg/min, preferably 2.0 dg/min or less, preferably 1.5 dg/min or less, preferably 1.2 dg/min or less, more preferably between 0.5 and 1.0 dg/min, more preferably between 0.6 and 0.8 dg/min.
In another embodiment, the polymers of the invention have a melt flow index xe2x80x9cMIRxe2x80x9d of I21/I2 of 80 or more, preferably 90 or more, preferably 100 or more, preferably 125 or more.
In another embodiment the polymer has an I21 (as measured by ASTM 1238, condition F, at 190xc2x0 C.)(sometimes referred to as Flow Index) of 2.0 dg/min or less, preferably 1.5 dg/min or less, preferably 1.2 dg/min or less, more preferably between 0.5 and 1.0 dg/min, more preferably between 0.6 and 0.8 dg/ min and an I21/I2 of 80 or more, preferably 90 or more, preferably 100 or more, preferably 125 or more and has one or more of the following properties in addition:
(a) Mw/Mn of between 15 and 80, preferably between 20 and 60, preferably between 20 and 40. Molecular weight (Mw and Mn) are measured as described below in the examples section;
(b) an Mw of 180,000 or more, preferably 200,000 or more, preferably 250,000 or more, preferably 300,000 or more;
(c) a density (as measured by ASTM 2839) of 0.94 to 0.970 g/cm3; preferably 0.945 to 0.965 g/cm3; preferably 0.950 to 0.960 g/cm3;
(e) a residual metal content of 5.0 ppm transition metal or less, preferably 2.0 ppm transition metal or less, preferably 1.8 ppm transition metal or less, preferably 1.6 ppm transition metal or less, preferably 1.5 ppm transition metal or less, preferably 2.0 ppm or less of Group 4 metal, preferably 1.8 ppm or less of Group 4 metal, preferably 1.6 ppm or less of Group 4 metal, preferably 1.5 ppm or less of Group 4 metal, preferably 2.0 ppm or less zirconium, preferably 1.8 ppm or less zirconium, preferably 1.6 ppm or less zirconium, preferably 1.5 ppm or less zirconium(as measured by Inductively Coupled Plasma Optical Emission Spectroscopy (ICPAES) run against commercially available standards, where the sample is heated so as to fully decompose all organics and the solvent comprises nitric acid and, if any support is present, another acid to dissolve any support (such as hydrofluoric acid to dissolve silica supports) is present;
(f) 35 weight percent or more high weight average molecular weight component, as measured by size-exclusion chromatography, preferably 40% or more. In a particularly preferred embodiment the higher molecular weight fraction is present at between 35 and 70 weight %, more preferably between 40 and 60 weight %.
In a preferred embodiment the catalyst composition described above is used to make a polyethylene having a density of between 0.94 and 0.970 g/cm3 (as measured by ASTM D 2839) and an I2 of 0.5 or less g/10 min or less
In another embodiment the catalyst composition described above is used to make a polyethylene having an I21 of less than 10 and a density of between about 0.940 and 0.950 g/cm3 or an I21 of less than 20 and a density of about 0.945g/cm3 or less.
In another embodiment, the polymer of the invention is made into a pipe by methods known in the art. For pipe applications, the polymers of the invention have a I21 of from about 2 to about 10 dg/min and preferably from about 2 to about 8 dg/min. In another embodiment, the pipe of the invention satisfies ISO qualifications.
In another embodiment, the catalyst composition of the present invention is used to make polyethylene pipe able to withstand at least 50 years at an ambient temperature of 20xc2x0 C., using water as the internal test medium and either water or air as the outside environment (Hydro static (hoop) stress as measured by ISO TR 9080).
In another embodiment, the polymer has a notch tensile test (resistance to slow crack growth) result of greater than 150 hours at 3.0 MPa, preferably greater than 500 hours at 3.0 MPa and more preferably greater than 600 hours at 3.0 mPa. (as measured by ASTM-F1473).
In another embodiment, the catalyst composition of the present invention is used to make polyethylene pipe having a predicted S-4 Tc for 110 mm pipe of less than xe2x88x925xc2x0 C., preferably of less than xe2x88x9215xc2x0 C. and more preferably less than xe2x88x9240xc2x0 C. (ISO DIS 13477/ASTM F1589).
In another embodiment, the polymer has an extrusion rate of greater than about 17 lbs/hour/inch of die circumference and preferably greater than about 20 lbs/hour/inch of die circumference and more preferably greater than about 22 lbs/hour/inch of die circumference
The polyolefins of the invention can be made into films, molded articles (including pipes), sheets, wire and cable coating and the like. The films may be formed by any of the conventional techniques known in the art including extrusion, co-extrusion, lamination, blowing and casting. The film may be obtained by the flat film or tubular process which may be followed by orientation in a uniaxial direction or in two mutually perpendicular directions in the plane of the film to the same or different extents. Orientation may be to the same extent in both directions or may be to different extents. Particularly preferred methods to form the polymers into films include extrusion or coextrusion on a blown or cast film line.
In another embodiment, the polymer of the invention is made into a film by methods known in the art. For film application, the polymers of the invention have a I21 of from about 2 to about 50 dg/min, preferably from about 2 to about 30 dg/min, even more preferably from about 2 to about 20 dg/min, still more preferably about 5 to about 15 dg/min and yet more preferably from about 5 to about 10 dg/min.
In another embodiment, the polymer has an MD Tear of 0.5 mil (13xcexc) film of between about 5 g/mil and 25 g/mil preferably, between about 15 g/mil and 25 g/mil, and more preferably between about 20 g/mil and 25 g/mil.
The films produced may further contain additives such as slip, antiblock, antioxidants, pigments, fillers, antifog, UV stabilizers, antistats, polymer processing aids, neutralizers, lubricants, surfactants, pigments, dyes and nucleating agents. Preferred additives include silicon dioxide, synthetic silica, titanium dioxide, polydimethylsiloxane, calcium carbonate, metal stearates, calcium stearate, zinc stearate, talc, BaSO4, diatomaceous earth, wax, carbon black, flame retarding additives, low molecular weight resins, hydrocarbon resins, glass beads and the like. The additives may be present in the typically effective amounts well known in the art, such as 0.001 weight % to 10 weight %.
In another embodiment, the polymer of the invention is made into a molded article by methods known in the art, for example, by blow molding and injection-stretch molding. For molded applications, the polymers of the invention have a I21 of from about 20 dg/min to about 50 dg/min and preferably from about 35 dg/min to about 45 dg/min.
In another embodiment, the polymers of the invention, including those described above, have an ash content less than 100 ppm, more preferably less than 75 ppm, and even more preferably less than 50 ppm is produced. In another embodiment, the ash contains negligibly small levels of titanium as measured by Inductively Coupled Plasma/Atomic Emission Spectroscopy (ICPAES) as is well known in the art.
In another embodiment, the polymers of the invention, contain a nitrogen containing ligand detectable by High Resolution Mass Spectroscopy (HRMS) as is well known in the art.